Red Bull RB9 Renault

[PhillipM]

It makes a sliding rear end easier to catch and easier to hold near the limit, because the tyre begins to slip slightly on as the pulse is applied then stops and the carcass relaxes as the pulse drops off, which helps with feedback and feel to the driver about where the limit is, which may well be a great thing to help preserve the current Pirelli's.

If you had perfect traction and tyres that could take being stressed to 100% every lap, you wouldn't do it, as it's slower, but we know that's far from the case at the moment.

I don't know what you are basing this information on, but in my experience there is no way in hell that pulsing the drive torque is going to help feedback to the driver. Quite the opposite. Additionally it will result in less overall grip for the reasons of tyre relaxation lengths and load sensitivity that I mentioned before. But if you want to continue pushing the belief that oscillating a tyre's torque or load is going to give you any improvement of grip or stability then I'm not going to continue arguing. I suggest reading up a bit on tyre dynamics before making such authoritative but completely hand waving statements.

Maybe you ought to try a bit of research yourself before rubbishing others, it's been used for 30-40 years in the bike world, everything from MotoGP to flattrack and motocross, it's been tried for dakar and rallying, it's in use for Autograss and there were rumours of it being tested in the turbo era for F1 too.

What was that about hand waving authoritative statements again?

[Tim.Wright]

Whatever... why don't you try and explain it then? What exactly is the mechanism that give the extra grip? Do you really understand how it works or are you basing your "knowledge" on anecdotal evidence?

It doesn't make any sense to oscillate anything to get the tyres to grip. I've explained this in phsyical terms already with no handwaving whatsoever.

I'm all ears if you feel like doing the same.

[PhillipM]

It's not to get the tyres to grip, as you would realise if you actually read my post before jumping up and down and shouting.

[Tim.Wright]

feedback, stability whatever its all grip related.

I'm still of the opinion its of no use on asphalt circuit racing.

[PhillipM]

Well, there's been a whole lot of top end and championship winning teams on tarmac over the last few decades that are obviously of a differing opinion.
Feedback and the ability to easily hold the car on the edge of slip are of just as much concern as outright grip.

[djos]

I'm with Tim on this, in an F1 setting torque pulsing is useless, it would make the car nervous as hell to drive and that's the last thing an F1 driver wants!

[PhillipM]

The point of it is to do exactly the opposite, compromise ultimate performance in favour of making the package easier to hold at the limit.

[djos]

The point of it is to do exactly the opposite, compromise ultimate performance in favour of making the package easier to hold at the limit.

Sounds completely counterintuitive!

[PhillipM]

Possibly not if you have a tyre that's very sensitive to loadings and slip....

[djos]

Possibly not if you have a tyre that's very sensitive to loadings and slip....

Actually it sounds to me like that type of system would merely torture the tires even more?

[chip mcdonald]

KERS analog TC system:

[...]

You can do this analog with capacitance, and all sorts of pre-21st century ways of getting D/C rectification.

[...]

via Scarbs Red Bull KERS: Floor Mounted Super Capacitors?

http://scarbsf1.files.wordpress.com/201 ... percap.jpg

Well, I wasn't just suggesting they're using capacitors, but that there are interesting attributes to capacitors in both the *timing* of how they discharge/charge, and what happens to the *frequency* of a "signal" (in this case, back EMF from the KERS motor).

What is going on post-ECU, and is being "reported" back to the ECU, can hide a lot IMO.

One basic thing would be a scenario involving using capacitors as a series front-end to the main battery back, in such a way that it "smooths" out the frequency of the difference in the KERS motor being under a load/not being under a load. In that way you could make a bypass circuit that actually would use the tire-slip overrun to momentarily charge a cap, and then have it release a predictable time later.

In this way, you'd both dampen any non-continuous wheel acceleration, with the added bonus of having that "wasted" energy recycled back to the KERS motor. In that way, the ECU wouldn't "see" what's going on.

Sort of a KERS "buffer".

I could think of a few other "invisible to ECU" scenarios, but ... $.10 from my armchair.

[raymondu999]

The point of it is to do exactly the opposite, compromise ultimate performance in favour of making the package easier to hold at the limit.

Make the package easier to drive (on the limit) by having an unpredictable torque map with peaks and troughs?

[PhillipM]

It doesn't give an unpredicatable torque map with peaks and troughs, it just puts a low frequency oscillation over the top of it. You've already got a lot of high frequency oscillations there, I don't see anyone talking about those.
A driver can't react to tyre slip as fast as the tyre itself does, so the aim is to stop the tyre slipping when it starts with the oscillation (like ABS in reverse) and let the driver sense the yaw instead, rather than just spin the wheels up.

[Chalky]

PhillipM you are completely correct, you clearly understand the characteristics engine torque and forms of traction control employed to make torque more desirable to the end user.

[Worky68]

All missing the obvious

It is Kers harvesting under traction.

I posed this question to Peter Windsor last year, and he confirmed on his podcast that KERs harvesting was being carried out under part throttle conditions.

Also, bear in mind, webber came to almost a complete standstill, floored it, the car was square, almost no lateral load.
One would suggest that the rate of load applied by the unit would increase exponentially (gear dependant) as revs get closer to the peak torque number, in conjunction with rev limiter, it may have set up the harmonic we are seeing.